1. Field of the Invention
Generally, the present disclosure relates to the field of integrated circuits, and, in particular, to integrated circuits including capacitors having different capacitor dielectrics.
2. Description of the Related Art
Integrated circuits typically include a large number of circuit elements, which form an electric circuit. In addition to active devices such as, for example, field effect transistors and/or bipolar transistors, integrated circuits may include passive devices such as resistors, inductances and/or capacitors.
Types of capacitors that may be provided in integrated circuits include metal-insulator-metal capacitors. Metal-insulator-metal capacitors may be provided in additional interconnect levels, which are provided in addition to interconnect levels wherein electrically conductive lines connecting circuit elements of integrated circuits are provided.
Metal-insulator-metal capacitors may be used as decoupling capacitors in CMOS logic integrated circuits to minimize voltage drops at the power grids. In such decoupling capacitors, thin films of a high-k dielectric material may be employed as a capacitor dielectric to obtain a high capacitance density of the decoupling capacitors and a low leakage current. Other applications of metal-insulator-metal capacitors include filter and analog capacitors, for example, in analog-to-digital converters or digital-to-analog converters, radio frequency coupling capacitors and radio frequency bypass capacitors in radio frequency oscillators, resonator circuits and matching networks.
In many applications of integrated circuits, such as integrated circuits for computers, consumer electronics, communication electronics and automotive electronics, nonvolatile embedded memory is desired. Types of nonvolatile memory include floating gate-based flash memory. However, integrating floating gate-based flash memory cells into integrated circuits that also include circuitry of another type, such as, for example, logic circuitry, may have issues associated therewith, in particular due to the relatively high process complexity of the formation of floating gate-based flash memory cells. Typically, more than eight additional photo masks may be required when floating gate-based flash memory cells are provided in an integrated circuit, in addition to photo masks that are used for forming other devices of the integrated circuit. Furthermore, in the operation of floating gate-based flash memory cells, relatively high voltages may be required, which may lead to further issues due to the need for high voltage transistors in the integrated circuit.
As an alternative to floating gate-based flash memory, other types of nonvolatile memory have been proposed, which include spin-transfer torque magnetoresistive random access memory (STT-MRAM), phase-change memory (PCM) and resistive random access memory (RRAM). However, using these techniques in embedded applications may be associated with issues related to technology maturity, cost and compatibility with processes for the manufacturing of logic circuits.
Embodiments of the present disclosure provide semiconductor structures and methods for the formation thereof which may provide an improved integration of nonvolatile memory into integrated circuits.